Being a brainless git? Though I'm not sure that is illegal, so it seems doubtful.

The fire brigade were only interested in putting out the fire and making sure there was nothing dangerous in his sheds.

I suppose the neighbour on the other side could sue him, as he's the only one who's had any real damage. But that sort of thing is probably more hassle than it's worth. I think various people's washing is going to stink quite bit, but I didn't see any that was actually on fire. I can still smell the smoke around the flat though.